bug#53591: Audacity can't find FFmpeg

bug#53591: Audacity can't find FFmpeg

[Leo Famulari]

Although Audacity 3.1.3 includes FFmpeg in its direct dependencies, it
does not keep a reference to it and cannot find it at runtime.

This is a regression from Audacity 2.4.2.

------
$ git describe
v1.3.0-15323-gf00ed43653
$ guix gc --references $(./pre-inst-env guix build --no-grafts audacity) | grep ffmpeg
------

bug#53591: Audacity can't find FFmpeg

[Leo Famulari]

On Thu, Jan 27, 2022 at 06:14:30PM -0500, Leo Famulari wrote:
> Although Audacity 3.1.3 includes FFmpeg in its direct dependencies, it
> does not keep a reference to it and cannot find it at runtime.

One consequence is that Audacity can't read Ogg files containing Opus or
Vorbis audio, or any other format delegated to FFmpeg, for example, this
file:

https://dl.espressif.com/dl/audio/ff-16b-2c-44100hz.ogg <-- downloads
with an ".ogx" extension

VLC, on the other hand, plays it fine.

Testing with the previous version of audacity (2.4.2), the .ogx file is
opened using FFmpeg, as shown in the "opening..." progress dialog box.

bug#53591: Audacity can't find FFmpeg

[Leo Famulari]

Between Audacity 2.4.2 and 3.1.3, upstream changed how Audacity finds
FFmpeg. It no longer links to it but instead loads it at runtime:

https://github.com/audacity/audacity/issues/2161

I detailed my hapless attempts to do that in the upstream bug report:

https://github.com/audacity/audacity/issues/2489

Any advice is most welcome!

bug#53591: [PATCH] gnu: audacity: Add fallback to locate ffmpeg via pkg-config.

[Liliana Marie Prikler]

* gnu/packages/patches/audacity-ffmpeg-fallback.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it here.
* gnu/packages/audio.scm (audacity)[patches]: Use it here.
[inputs]: Add back ffmpeg.
---
 gnu/local.mk                                  |  1 +
 gnu/packages/audio.scm                        |  2 +
 .../patches/audacity-ffmpeg-fallback.patch    | 61 +++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 gnu/packages/patches/audacity-ffmpeg-fallback.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 96e6cb08f4..898e8e92e3 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -859,6 +859,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/ath9k-htc-firmware-gcc-compat.patch	\
   %D%/packages/patches/ath9k-htc-firmware-objcopy.patch		\
   %D%/packages/patches/atlas-gfortran-compat.patch		\
+  %D%/packages/patches/audacity-ffmpeg-fallback.patch	\
   %D%/packages/patches/audiofile-fix-datatypes-in-tests.patch	\
   %D%/packages/patches/audiofile-fix-sign-conversion.patch	\
   %D%/packages/patches/audiofile-CVE-2015-7747.patch		\
diff --git a/gnu/packages/audio.scm b/gnu/packages/audio.scm
index feccf662b0..22dd88ef0c 100644
--- a/gnu/packages/audio.scm
+++ b/gnu/packages/audio.scm
@@ -738,6 +738,7 @@ (define-public audacity
        (sha256
         (base32
          "189agx11361k9j958s6q5bngnnfx0rwaf0dwbjxy6fwvsb1wv3px"))
+       (patches (search-patches "audacity-ffmpeg-fallback.patch"))
        (modules '((guix build utils)))
        (snippet
         ;; Remove bundled libraries.
@@ -768,6 +769,7 @@ (define-public audacity
            lame
            linux-libre-headers
            flac
+           ffmpeg
            libid3tag
            libjpeg-turbo
            libmad
diff --git a/gnu/packages/patches/audacity-ffmpeg-fallback.patch b/gnu/packages/patches/audacity-ffmpeg-fallback.patch
new file mode 100644
index 0000000000..9e88973241
--- /dev/null
+++ b/gnu/packages/patches/audacity-ffmpeg-fallback.patch
@@ -0,0 +1,61 @@
+From 3c20057d0cbbbed453a692d4dd4589d865808024 Mon Sep 17 00:00:00 2001
+From: Liliana Marie Prikler <liliana.prikler@gmail.com>
+Date: Sat, 29 Jan 2022 10:44:44 +0100
+Subject: [PATCH] Add pkg-config fallback for locating ffmpeg.
+
+---
+ libraries/lib-ffmpeg-support/CMakeLists.txt      |  8 ++++++++
+ libraries/lib-ffmpeg-support/FFmpegFunctions.cpp | 12 ++++++++++++
+ 2 files changed, 20 insertions(+)
+
+diff --git a/libraries/lib-ffmpeg-support/CMakeLists.txt b/libraries/lib-ffmpeg-support/CMakeLists.txt
+index 8c5f06d7c..00810e4d0 100644
+--- a/libraries/lib-ffmpeg-support/CMakeLists.txt
++++ b/libraries/lib-ffmpeg-support/CMakeLists.txt
+@@ -1,5 +1,7 @@
+ 
+ if (${_OPT}use_ffmpeg)
++   pkg_check_modules(FFMPEG libavcodec libavformat libavutil)
++
+    set( SOURCES
+       FFmpegTypes.h
+ 
+@@ -100,6 +102,12 @@ if (${_OPT}use_ffmpeg)
+       list(APPEND DEFINITIONS PRIVATE _DARWIN_C_SOURCE )
+    endif()
+ 
++   if (FFMPEG_FOUND)
++      pkg_get_variable(LIBAVCODEC_LIBDIR libavcodec libdir)
++      list(APPEND DEFINITIONS PRIVATE
++                  "-DFFMPEG_PC_LIBDIR=L\"${LIBAVCODEC_LIBDIR}\"")
++   endif()
++
+    audacity_library( lib-ffmpeg-support "${SOURCES}" "${LIBRARIES}"
+       "${DEFINITIONS}" ""
+    )
+diff --git a/libraries/lib-ffmpeg-support/FFmpegFunctions.cpp b/libraries/lib-ffmpeg-support/FFmpegFunctions.cpp
+index 66d085a0b..4eeb4aed3 100644
+--- a/libraries/lib-ffmpeg-support/FFmpegFunctions.cpp
++++ b/libraries/lib-ffmpeg-support/FFmpegFunctions.cpp
+@@ -238,6 +238,18 @@ struct FFmpegFunctions::Private final
+       if (library->IsLoaded())
+          return library;
+ 
++#if defined(FFMPEG_PC_LIBDIR)
++      {
++         static const wxString libdir{FFMPEG_PC_LIBDIR};
++         const wxString fullName = wxFileName(libdir, libraryName).GetFullPath();
++
++         auto library = std::make_shared<wxDynamicLibrary>(fullName);
++
++         if (library->IsLoaded())
++            return library;
++      }
++#endif
++
+       // Loading has failed.
+       // wxLogSysError doesn't report errors correctly on *NIX
+ #if defined(_WIN32)
+-- 
+2.34.0
+
-- 
2.34.0

bug#53591: [PATCH] gnu: audacity: Add fallback to locate ffmpeg via pkg-config.

[Leo Famulari]

On Sat, Jan 29, 2022 at 06:54:54PM +0100, Liliana Marie Prikler wrote:
> * gnu/packages/patches/audacity-ffmpeg-fallback.patch: New file.
> * gnu/local.mk (dist_patch_DATA): Add it here.
> * gnu/packages/audio.scm (audacity)[patches]: Use it here.
> [inputs]: Add back ffmpeg.

Well, this is fantastic Liliana! It works great.

Can you add a comment to 'audacity-ffmpeg-fallback.patch' with a link to
<https://issues.guix.gnu.org/53591>?

bug#53591: [PATCH] gnu: audacity: Add fallback to locate ffmpeg via pkg-config.

[Liliana Marie Prikler]

Am Samstag, dem 29.01.2022 um 14:53 -0500 schrieb Leo Famulari:
> On Sat, Jan 29, 2022 at 06:54:54PM +0100, Liliana Marie Prikler
> wrote:
> > * gnu/packages/patches/audacity-ffmpeg-fallback.patch: New file.
> > * gnu/local.mk (dist_patch_DATA): Add it here.
> > * gnu/packages/audio.scm (audacity)[patches]: Use it here.
> > [inputs]: Add back ffmpeg.
> 
> Well, this is fantastic Liliana! It works great.
> 
> Can you add a comment to 'audacity-ffmpeg-fallback.patch' with a link
> to <https://issues.guix.gnu.org/53591>?
Done and pushed.

bug#53591: closed (Re: [PATCH] gnu: audacity: Add fallback to locate ffmpeg via pkg-config.)

[Leo Famulari]

On Sun, Jan 30, 2022 at 07:19:02AM +0000, GNU bug Tracking System wrote:
> From: Liliana Marie Prikler <liliana.prikler@gmail.com>
> Am Samstag, dem 29.01.2022 um 14:53 -0500 schrieb Leo Famulari:
> > Well, this is fantastic Liliana! It works great.
> > 
> > Can you add a comment to 'audacity-ffmpeg-fallback.patch' with a link
> > to <https://issues.guix.gnu.org/53591>?
> Done and pushed.

I'm not sure what happened, but it seems I failed to test this fix
properly.

Audacity still does not keep a reference to FFmpeg, and it cannot
Opus-encoded files (among many other types of encodings):

------
$ git describe
v1.3.0-15695-gba60aede97
$ $(./pre-inst-env guix build --no-grafts audacity) | grep ffmpeg 
$
------

This is the file to test with:

https://dl.espressif.com/dl/audio/ff-16b-2c-44100hz.opus

I've reopened this bug.

bug#53591: closed (Re: [PATCH] gnu: audacity: Add fallback to locate ffmpeg via pkg-config.)

[Leo Famulari]

On Fri, Feb 04, 2022 at 05:32:30PM -0500, Leo Famulari wrote:
> Audacity still does not keep a reference to FFmpeg, and it cannot
> Opus-encoded files (among many other types of encodings):

On #guix, lilyp found the culprit:

http://logs.guix.gnu.org/guix/2022-02-04.log#235737

... an extra "L" character in the patch file:

https://issues.guix.gnu.org/53591#3-lineno78

Fixed with commit 04cd0ece6219fef2f18ee62442a913a02495fb50